Cannabis addiction: a risk for patients?
A 2018 study commissioned by the German Federal Ministry of Health, known as the CaPRis study, found that 6.1 % of 18- to 64-year-olds in Germany had used or used cannabis in the 12 months prior to the survey (1). Approximately 1% of this age group had some form of cannabis use disorder.
In principle, any substance that has a psychotropic effect can, to varying degrees, trigger a desire in the user to repeat the use and thus induce dependence.
With this in mind, it is understandable that patients taking medical cannabis may be concerned about potentially developing cannabis addiction through their therapy. But how exactly is cannabis addiction defined? And how high is the actual risk of addiction for patients using medical cannabis?
Definition of cannabis addiction
The definition of cannabis addiction is given by a fixed classification system, the ICD-10. This system is an international statistical classification of diseases and health problems published by the World Health Organization (WHO) and used by contract physicians in Germany when making diagnoses. According to the ICD-10 classification system, cannabis dependence is referred to as “cannabis use disorder.” There are two degrees of cannabis use disorder:
- Harmful use of cannabis
- Cannabis addiction
Harmful use of cannabis
Harmful use of cannabis is defined as a pattern of excessive cannabis use that can cause physical or mental health harm. It is then further categorized according to the harm caused and the specific symptoms. For example, one of the criteria is the occurrence of negative social consequences due to cannabis use.(2)
Cannabis addiction
Cannabis dependence can be considered a more severe form of cannabis abuse. For cannabis dependence to be diagnosed, three of the following six criteria must be present(2):
- Strong desire or compulsion to use cannabis;
- Lack of control over consumption in terms of onset, end, and quantity;
- Physical withdrawal symptoms;
- Tolerance;
- Neglecting everyday life to focus on consumption;
- Continued consumption despite harmful consequences;
What are the symptoms of cannabis withdrawal?
The occurrence of physical withdrawal symptoms is a criterion for the diagnosis of cannabis addiction. The presence of addiction to cannabis may manifest itself in the form of the following withdrawal symptoms (2):
- Sleep disorders
- Irritability
- Unrest
- Appetite disorders
The symptoms of cannabis withdrawal are usually not severe or even life-threatening. For example, there are no documented deaths or serious adverse health effects attributable to cannabis withdrawal. On average, cannabis withdrawal symptoms last a few days.(2)
Addiction to medical cannabis
According to the CaPRis study mentioned above, only a proportion of those who use cannabis regularly suffer from some form of cannabis addiction (2) . Among those who use cannabis for therapeutic reasons, this proportion is even lower. To understand the extent to which patients who use medical cannabis may become addicted to cannabis, it is useful to consider whether they meet the criteria listed above.
Tolerance
The development of tolerance is one of the main features of any substance dependence. Over time, the desired effect of a substance wears off, and an increase in dose is required to achieve the same effect as before. This is a very common feature of almost all substances that act on the central nervous system, whether used for medical purposes or consumed recreationally.(2) Substances for which tolerance development can occur, in addition to cannabis, include opioids (e.g., morphine) and benzodiazepines (such as Valium®). However, in the case of cannabis, many months or even years usually pass before patients require an increased dose to achieve sufficient efficacy.(2)
Withdrawal symptoms
Withdrawal symptoms are also a common phenomenon in substance addictions.This is especially true when substance use is abruptly interrupted. If a patient is using cannabis for medical reasons, it is important that the doctor weighs up whether interrupting treatment may have adverse health effects and adverse social consequences.(2)
Strong desire or compulsion to use cannabis
According to ICD-10, one of the main symptoms of substance dependence is a strong, constant desire to use a substance. This is usually present despite the harmful effects on health. However, in the case of medical cannabis, this strong desire is additionally linked to the fact that it can alleviate the symptoms of another disease. A patient’s desire to be treated is justified, so even the desire for cannabis in this case is not necessarily a sign of addiction.(2)
Negative social consequences
In substance abuse disorders, the person may hide his use from his family or friends. The fear: if he does not do this, his substance use may be criticized by his family members and close friends. Both situations can lead to “negative social consequences.” The use of medical cannabis, on the other hand, does not take into account the opinion of the patient’s environment, but rather the actual physical and psychological effects on the patient.(2)
Recommendations
Through effective risk management, problems related to potential dependence on cannabis can be made visible and intercepted in a timely manner. The following six recommendations can help to make cannabis treatment as safe as possible(3) :
- Attention to the THC:CBD ratio It is known that a high dose of THC can increase the susceptibility to addiction. At the same time, it is known that CBD can have a dependence-reducing effect. Therefore, it is important that the prescribing physician optimally adjusts the ratio of THC to CBD to prevent the development of dependence.
- Guarantee safe supply Patients should absolutely have access to a reliable medical cannabis product. The black market poses widespread risks, such as illegality or quality disparities, as well as the use of chemically treated products.
- Attention to the THC:CBD ratio It is known that a high dose of THC can increase the susceptibility to addiction. At the same time, it is known that CBD can have a dependence-reducing effect. Therefore, it is important that the prescribing physician optimally adjusts the ratio of THC to CBD to prevent the development of dependence.
- Guarantee safe supply Patients should absolutely have access to a reliable medical cannabis product. The black market poses widespread risks, such as illegality or quality disparities, as well as the use of chemically treated products.
- Personalised treatment Treatment with medicinal cannabis can be customised. The following aspects can be adapted depending on the disease state and individual needs:
- Personalisierte Behandlung Eine Behandlung mit medizinischem Cannabis kann individuell gestaltet werden. Folgende Aspekte können je nach Krankheitszustand und individuellen Bedürfnissen angepasst werden:
- Ratio of THC to CBD
- Frequency of use
- Mode of administration
- The risk of dependence also differs depending on the disease and the patient. Genetic variations in cannabis receptors and metabolism may play a role in the future.
- Weighing patient need against health risk. Any risk of dependence on medical cannabis must be weighed against alternative medicines, some of which themselves have a potentially higher abuse potential. When prescribing, the doctor and patient need to consider this trade-off together, especially if use is likely to be long-term.
Conclusion
Cannabis addiction is a serious and real phenomenon that affects many people worldwide. For a diagnosis to be made, several criteria must be met. In the case of medical cannabis, it is important to consider the medical needs of cannabis patients when diagnosing cannabis addiction. Moreover, the risk of addiction can be reduced if the prescribing doctor’s instructions are strictly followed.
Sources
1. Cannabis: Potenzial und Risiken (CaPRis) [Internet]. [cited 2023 Jan 31]. Available from: https://www.bundesgesundheitsministerium.de/service/publikationen/details/cannabis- potenzial-und-risiken-capris.html
2. Müller-Vahl KR, Grotenhermen F. Cannabis und Cannabinoide: in der Medizin. 1. edition. MWV Medizinisch Wissenschaftliche Verlagsgesellschaft; 2019. 359 p.
3. Schlag AK, Hindocha C, Zafar R, Nutt DJ, Curran HV. Cannabis based medicines and cannabis dependence: A critical review of issues and evidence. J Psychopharmacol Oxf Engl. 2021 Jul;35(7):773–85.
4. Fischer B, Russell C, Sabioni P, van den Brink W, Le Foll B, Hall W, et al. Lower-Risk Cannabis Use Guidelines: A Comprehensive Update of Evidence and Recommendations. Am J Public Health. 2017 Aug;107(8):e1–12.
